A new role for PGRP-S (Tag7) in immune defense: lymphocyte migration is induced by a chemoattractant complex of Tag7 with Mts1

PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4⁺ and CD8⁺ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.     

Shell as an indicator of the growth rate of freshwater gastropods of the family Bithyniidae

Snails of the family Bithyniidae (Gastropoda: Prosobranchia) of 29 populations (14 014 individuals) from West Siberia were examined. Guidelines for studying the growth rate of the Gastropoda based on shells were proposed. Data on the effect of abiotic and biotic factors on the Gastropoda growth rate were analyzed. The effect of trematode parthenitae on the shell growth rate was investigated for Bithynia troscheli (Paasch, 1842).     

A quantitative estimation of the role of bithyniidae snails (gastropoda: Prosobranchia) in the ecosystems of the southern part of Western Siberia (Russia)

This study describes the species diversity, abundance and biomass of gastropods in the ecosystems of the southern part of Western Siberia (Karasuk River and Krotovo Lake, Karasukskii district, Novosibirsk Oblast). Eighteen species belonging to seven families were recorded, Lymnaeidae, Planorbidae, Bulinidae, Bithynhdae, Physidae, Succineidae, and Zonitidae. The percentage of Bithyniidae snails was assessed in comparison to other gastropods and in regard to the species diversity, abundance, and biomass. The role of Bithyniidae mollusks as a host for trematodes was assessed. The biodiversity of mollusks and trematodes was studied using the Shannon-Weaver index.     

Temporal variation in prevalence and abundance of metacercariae in the pulmonate snail Lymnaea stagnalis in Chany Lake, West Siberia, Russia: long-term patterns and environmental covariates

Infrapopulations of trematode metacercariae were monitored in the snail Lymnaea stagnalis over 17 yr (1982-1999) at Chany Lake, Novosibirskaya Oblast', Russia. Eighteen trematode species were recorded. Patterns of occurrence varied from 4 species (Echinoparyphium aconiatum, Echinoparyphium recurvatum, Moliniella anceps, and Cotylurus cornutus) that persisted at relatively high prevalence (> 60% of samples) across sites, seasons, and years, to species that were very rare and sporadic in occurrence. The stability of the 4 common species was probably because of their occurrence either in a wide range of definitive hosts or in a host adapted to the extreme abiotic changes that occurred from year to year in these wetlands. The prevalence and mean abundance of C. cornutus were negatively correlated with water level in the wetlands; its prevalence was also correlated with water temperature. The mean abundance of M. anceps was positively correlated with water level. The most probable explanation for the cyclic dynamics of infections of the common species is change in population sizes and densities of definitive and intermediate hosts, which mediated cyclic alterations in water levels.     

Characteristics of the seasonal development of Schistogonimus rarus (Trematoda: Prosthogonimidae). An essay on quantitative estimation of the trematode in the ecosystem of the Malye Chany lake (south of Western Siberia)

Quantitative estimation of the trematode Schistogonimus rarus at the stage of cercaria is carried out in the ecosystem of the Malye Chany lake, south of Western Siberia, on the base of long-term data obtained in 1995-2002. Average daily emission of the S. rarus cercaria was shown to be significantly higher in larger mollusc hosts (p < 0.01), by the results of laboratory investigations. Moreover, significant decrease of the average daily emission of the S. rarus cercaria from June to July is established (p < 0.01). It was revealed, that emission of the S. rarus cercaria in the south of Western Siberia (both in natural and laboratory conditions) lasts no more than 50 days and is finished in August. The infestation rate of the mollusc host Bithynia troschelii by the S. rarus parthenites varied from 0.28 to 1.44 % in different years and correlated with the water temperature at first ten days of June (r = 0.75). Flow of the S. rarus cercaria (specimens per square meter) was estimated on the base of the quantitative characteristics of the cercaria emission, data on the infestation rate of the host population, and data on the host abundance. The flow of the cercaria varied from 6000 (in 1998) up to 330000 (in 2000) per season and correlated with the water temperature in third ten days of June (r = 0.71).     

Characteristics of opisthorchiasis foci in southern West Siberia

Natural foci of opistorchiasis were studied in southern West Siberia. It has been shown that the foci are of two biocenotic groups: floodplain-river and lake-interfluve. The main difference between them is that in the former intermediate hosts of opistorchides are commercial Cyprinidae fish and final hosts are humans and domestic carnivores, whereas in the latter, intermediate hosts are noncommercial Cyprinidae fish, wild carnivores, and muskrat. Floodplain-river foci are associated with river basins in the north of Baraba, big and small tributaries of the Ob and Irtysh rivers, as well as euthrophic lakes within floodplains of the rivers. Lake-interfluve foci are associated with euthrophic and dystrophic lakes in the river floodplains which do not communicate with the Ob-Irtysh water system. They are located in North Kulunda and in the south of Baraba lowland.     

Distribution of trematodes of the family Prosthogonimidae in river and lake ecological systems in the south of the Western Siberia

The results of long-term investigations (1994-2003) of an infection rate of trematodes of the family Prosthogonimidae in the first intermediate hosts (snails of the family Bithyniidae) and in the final hosts (birds) from a basin of the Chany Lake (Western Siberia) are discussed. A total of 1824 specimens of Bithynia tentaculata (L., 1758) and 7166 specimens of Opisthorchophorus troscheli (Paasch, 1842) have been collected from eight rivers and two lakes in the south of the Western Siberia. Data of incomplete helminthological dissection of 225 young water-fowl of 18 species were analyzed. Birds were obtained in July, August and September, 1996-2003 from the Chany lake basin. Maritas of the trematode family Prosthogonimidae were revealed in bursa Fabricii (26.12%) of seven bird species of two orders (Anseriformes and Gruiformes): Grey Lag-Goose Anser anser (L.) (Infection rate-28.6% +/- 12.1), Mallard Anas platyrhynchos L. (27.5% +/- 6.2), Shoveler--A. clypeata L. (22.2% +/- 13.9), Pochard Aythya ferina (L.) (51.7% +/- 9.3), Coot Fulica atra L. (28.6% +/- 5.6), Tufted Duck A. fuligula (L.) (1 case), Wigeon A. penelope L. (1 case). Average intensity of invasion is 5.8 marita specimens per infected bird. The maximal number of parasites (37 maritas), and also the highest average intensity of invasion are recorded for the Coot. The 342 maritas of the family Prosthogonimidae belong to three species: Prosthogonimus ovatus (Rud., 1803) (49.7%), P. cuneatus (Rud., 1809) (32.8%) and Schistogonimus rarus (Braun, 1901) (14.6%); these trematode species have been recorded in 35, 12 and 8 bird species, respectively. Grey Lag-Goose, Shoveler, Pochard and Tufted Duck are new host records for P. cuneatus in for Western Siberia. Parthenitae of trematodes (Prosthogonimidae) were revealed from eight populations of bithyniid snails. The infection rate of the trematodes (parthenitae and cercariae) in population of bithyniid snails from lake ecological system varied 6.55-54.4%, and in river ecological systems in was 0.6-4.2 %. The infection rate of trematodes (parthenitae and cercariae) of the first intermediate hosts was 2.64% that is significantly lower than that of the final hosts from the Chany Lake basin. Both O. troscheli and B. tentaculata were noted as the first intermediate hosts of prosthogonimid trematodes of three species: P. ovatus, P. cuneatus and S. rarus. All three species of trematode were found in three water reservoirs: Ob River (B. tentaculata), Kargat River (O. troscheli) and Chany Lake (O. troscheli). Thus it is found out that 39 bird species can be the final hosts of prosthogonimid trematodes. About a quarter of nestlings is infected with these trematodes. The infection rate of parthenitae in snails from the lake ecosystems is significantly higher than in the river ecosystems.     

Evolutionary pattern of the forewing shape in the Neotropical genus of jumping plant-lice (Hemiptera: Psylloidea: <Emphasis Type="Italic">Russelliana</Emphasis>)

Geometric morphometric and phylogenetic analyses, applied to 43 species of Russelliana, shed light on the evolution of insect wing shape. Unconstrained and constrained ordination techniques are introduced to detect patterns of the forewing shape variation within genus. Results show a high congruence between forewing shape variation and host-plant preference supporting monophyly of most phylogenetic groups in Russelliana. Reconstruction of the ancestral forewing state shows its similarity to a forewing shape of Solanaceae feeding species defined as ancestors by the phylogenetic study supporting a hypothesis as to a primary association of Russelliana with Solanaceae. In contrast to some other comparative studies on insect wing shape, results of the present study reveal a strong correlation between variation of forewing shape in Russelliana and its phylogeny. Potential influence of vicariant events and host shifts on the evolution of forewing shape is discussed.